JEFFERSON CITY, Mo. (AP) — Gov. Jay Nixon said Friday that Missouri school children should be spending more time in the classroom.

Nixon said he wants six days added to the state's academic calendar, a move he said would bring Missouri to the national average of 180 days. The governor said the proposed state budget he presents later this month will include funding to support a longer school year.

"To stay competitive in today's economy, Missouri's students should be in the classroom as much as their peers in other states," said Nixon, a Democrat. "Extending Missouri's school year by just six instructional days will bring our state in line with the national average while increasing educational opportunities for every student."

Missouri currently requires at least 174 days for districts with classes five days per week and at least 142 days for districts that have four-day weeks. State law also requires 1,044 hours of instructional time.

Figures from the Education Commission of the States show that as of 2011, more than half the states required at least 180-day school calendars. Alaska, Colorado and Michigan had shorter minimum school years than Missouri. The state's requirement for 1,044 hours put Missouri closer to the middle of the pack nationally.

The Missouri School Boards' Association said lengthening the school year could raise costs for personnel and operating facilities but that it is worthy of discussion. The association said some districts already exceed the minimum requirements.

"There is a lot of merit to the idea of extending the school year and providing students with increased instructional time," spokesman Brent Ghan said.

Mike Wood, a lobbyist for the Missouri State Teachers Association, said increasing the number of hours instead of the number of days might be more significant. He said the schedules used by high-performing districts could serve as a guide.

Nixon was traveling Friday to schools in Nixa in southwestern Missouri and Orrick, which is east of Kansas City. In addition to lengthening the academic year, the governor also called for expanding the A+ scholarship program and for increased funding to preschool education programs.

Under the scholarship program, students from participating high schools can earn a scholarship to cover tuition costs at public community colleges and technical schools. Students must meet requirements for academics, conduct and attendance and perform 50 hours of tutoring or mentoring service.

Nixon said his budget will include funding to expand the program to every Missouri school district. The governor's office said 148 out of 402 high schools now participate.

The governor said his proposed budget also will call for a restoration of funding for early childhood initiatives such as the Early Head Start program that were cut in the budget that took effect July 1.